A ski has length 1.8 m and uniform cross-section with width 90 mm and (total) thickness 12 mm. It has a composite sandwich structure with a core of maple wood (Ec = 12.62 GPa) and equal-thickness skins of Titanal (Es = 72 GPa). (a) When simply supported at the ends and subject to a central load of 400 N, the ski must not deflect by more than 100 mm. What is the required flexural rigidity? [10 marks] (b) The Titanal skin is available only in integer thicknesses, i.e., 1 mm, 2 mm, etc. What is the minimum available thickness to meet the required flexural rigidity? [8 marks] (c) When simply supported at the ends and subject to a central load of 400 N, and with a skin thickness of 1 mm, what is the maximum axial bending stress in (i) the skin, and (ii) the core? [7 marks]